3) In the developer console, type "record <name of demo>", without the quotes and replacing <name of demo> with whatever you want to name your demo. For instance, "record scuzzy1.dem":

After hitting enter you should see it tell you the recording started:

4) Hit ESC and everything you see will be recorded. If you are recording a demo of another player it's easiest to do through Spectator mode.

5) When you are done, go back into the developer console and type "stop" and hit enter. The screen will tell you the demo has stopped recording:

6) How to find that Demo on your computer. The demo is recorded within your TF2 folder. That is usually located in your "c:\Program Files\Steam\SteamApps\(your login name here)\tf2", like the following:

Enabling and Binding a Key to the Developer Console

Enabling and Binding a Key to the Developer Console

If your developer console does not appear when you hit the ` or ~ key then it probably isn't enabled.

1) Press ESC so you see the TF2 menu screen while you're in game:

2) Click on Options

3) Click on Advanced

4) Click on Enable Developer Console and hit "OK".

5) Find, at the very bottom of your keybinds, "Toggle Developer Console". It should say it's bound to `, if not, bind it to this key (it's the default and what everyone will tell you to do):